As is known in the art, there exists a class of phased array radar systems known as active electronically scanned array (AESA) radar systems. AESA radar systems transmit and receive radio frequency (RF) signals through a phased array antenna. Transmit and receive beams can be electronically formed and directed (or “pointed” or “steered” or “scanned”) by appropriate phasing of selected ones of antenna elements which make up the phased array antenna.
An angle at which the AESA directs a main antenna beam is referred to as a beam scan angle (or more simply a “scan angle”) and the entire angular range over which an AESA can scan the main beam is referred to as a scan angle range (or more simply “scan range”).
The further a phased array radar scans a beam off the antenna boresight (i.e. the greater the scan angle), the beam begins to broaden, resulting in scan loss. Thus, when AESA radar systems scan at angles approaching or reaching the outer limits of a scan angle range (e.g. extreme angles off the AESA boresight), the AESA experiences so-called scan loss and other errors which can reduce the effectiveness of the radar system.
Thus, to increase a scan range over which an AESA radar system can operate, radar systems may increase a dwell time and/or increase an RF signal power provided to the AESA at the extreme scan positions. Alternatively, or in addition to the above, in some embodiments, the scan range of a radar system may be increased by increasing the number of antenna elements in the phased array and/or by utilizing multiple AESAs in the radar system. While increasing the number of antenna elements in an AESA and/or utilizing multiple AESAs increases a scan range of a radar system, such approaches also result in a concomitant (and sometimes prohibitive) increase in the size, weight, power, and cost of the AESA and the radar system.